The present invention relates generally to electrical power conversion systems, and, more specifically, to providing a means to operate twelve volt to fourteen volt (12V-14V) equipment off of a vehicle electrical power system operating at a different voltage with the additional ability to control the operating states/parameters of a load using the vehicle""s existing electrical power bus as a communication medium.
Electrical power demands on automobiles and other vehicle electrical systems have been growing due to increasing requirements for electrical power by peripheral equipment and by the vehicle components themselves. This is because vehicle manufacturers are not only increasingly adding electrically powered features for convenience, but manufacturers are also increasingly replacing mechanically, hydraulically, and pneumatically powered components with electrically powered components, typically with the intent to increase both vehicle performance and component reliability while also reducing total vehicle weight. Increasing computerization of vehicles has also tended to increase the electrical power requirements of vehicle power systems.
However, conventional vehicle electrical systems, many of which operate at fourteen volts (14V) DC while running and use twelve volt (12V) batteries for starting, often cannot keep up with the anticipated electrical demands. This is partly due to the fact that low voltage systems require high current capacity when compared to higher voltage systems. High current capacity, in turn, requires a heavier gauge wiring system to accommodate the higher currents, which could lead to heavier wiring harnesses and larger resistive heat losses. These shortcomings could make conventional vehicle electrical systems unsatisfactory for many modern vehicles, and may lead to the need for higher-voltage electrical power systems.
To respond to these changing circumstances, vehicle manufacturers have explored different electrical system standards. One standard is a forty-two volt (42V) DC electrical power system while operating, but using a thirty-six volt (36V) battery for starting the vehicle engine or operating equipment while the engine is not running. Such higher-voltage systems might reduce wiring harness size and may increase the total electrical power available for practical vehicle use.
For many different reasons, some loads on a thirty-six volt to forty-two volt (36V-42V) electrical power system may continue to require power at about twelve volts to fourteen volts (12V-14V). For example, experience has shown that thicker twelve volt (12V) light bulb filaments are often more durable than the thinner higher voltage light bulb filaments, which are consequently often less rugged. Accordingly, there is a need in the art for a means of providing twelve volts to fourteen volts (12-14V) electrical power to vehicle components when the vehicle electrical power bus operates at a different voltage.
The present invention provides an electrical power conversion system for delivering electrical power to a load by converting electrical power received from an electrical power bus at a first voltage (V1) into electrical power at a second voltage (V2) to power the load. The system also provides a means to control the states and/or operating parameters of the load.
A load transmitter is used to output a communication signal containing encoded load information coupled onto the electrical power bus to control a load receiver or the load itself. The encoded load information may be made up of the desired load state, status, and address. The load transmitter is comprised of: a data encoder, which encodes the desired load state and address information into a data output; a data transmitter, which receives the data and transmits a communication signal; and a coupler, which then couples the communication signal onto the electrical power bus.
A load receiver is used to control the load and to convert the electrical power bus power provided at a first voltage (V1) into a load electrical power output at a second voltage (V2). The load receiver is comprised of a decoupler, which decouples the communication signal from the electrical power bus and isolates the load receiver from the electrical power bus; a data receiver, which receives the communication signal and which derives the encoded data therefrom; a data decoder to decode the encoded data and convert it into a converter signal; and a power converter, which receives the converter signal from the data decoder. The state or operating condition of the load can then be set via the converter signal, according to the desired load state and address information. The power converter also converts the electrical power from the electrical power bus at the first voltage (V1) into power at the second voltage (V2) for powering a load or load subsystem.
The load state, status, and address information may be used to identify and locate the load (or the associated power converter) and/or to set the load operating states or conditions (or the states and conditions of the associated power converter).
In this way, the electrical power system can feed loads at a second voltage (V2) when provided with an electrical power bus at a first voltage (V1), and the state of a load can be controlled.